CHICAGO (AP) — Northern Illinois communities that run "Polar Express" train rides every holiday season are getting the legal equivalent of a lump of coal in their stockings from the company that owns the rights to the name.

Park districts reported receiving letters from Warner Bros. telling them they have no legal right to use the name of the popular 1985 book and 2004 movie without permission, meaning they must pay to license future events or stop using the name.

In the letter, Susan Proctor, the company's Entertainment Anti-Piracy Director, explained the company believes that using the name will mislead people into thinking that Warner Bros. is somehow involved in these holiday events.

"In addition, your use of Warner Bros.' Intellectual Property dilutes the distinctiveness of 'the Polar Express' property by trading upon the goodwill and reputation which the public associates with the property," she wrote.

A Barrington Park District official said she spoke to the company's licensing agent and was told the license could cost as much as 30 percent of the gross for the event — a price tag the community just can't afford.

"That could sink the event, because we don't make that much," district Recreation Supervisor Jodi Krauss said.

Krauss and others say ditching the "Polar Express" name won't hurt the events' popularity, though Krauss said being forced to stop reading the story might.

Clarendon Hills Park District employee Kelly Smith said they'll be changing the name rather than getting into a legal fight or paying a licensing fee.

"We absolutely know we are going to give them a great event, we just know it won't be the 'Polar Express,'" she said. "It will be the Santa Train."

Still, the park district officials were left to wonder why, after so long, Warner Bros. was warning them now.

It turns out somebody tipped Warner Bros. off: Santa.

John Sullivan, who has played Santa in suburban Chicago for more than two decades, has been listing "Polar Express" events on his website.

Proctor said Sullivan made it easier to track down which communities had for years been naughty and not so nice. She added that if park districts have already sold tickets they can use the "Polar Express" name one last time.

The whole affair has Sullivan baffled.

"I'm kind of surprised by it because this is doing the book and the movie a lot of good," he said. "It's keeping them alive."

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